Bridge rectifier (Pollak–Graetz circuit)
Puente rectificador (circuito de Pollak-Graetz)
- Date
- 1895-1896 · confidence high
- Place
- Frankfurt am Main, Germany
- Credited to
- Karol Pollak
- Field
- Matter & energy
⚠️ Disputed: the sources disagree.
What it is
Pollak patented a four-rectifier bridge circuit that converts alternating current into direct current by flipping the negative half of the waveform, and took it into commercial production at his accumulator factory in Frankfurt.
Pollak patented the circuit in December 1895 (UK) and January 1896 (Germany), and was already manufacturing it commercially when Leo Graetz published a similar circuit in 1897; despite this, the circuit is popularly known as the "Graetz bridge".
What it led to
- Modern DC power supplies
- Integrated four-diode bridge rectifiers (from the 1950s)
- Semiconductor-based power electronics